Rodless pump



Nov. 9, 1948. R. c. FERGUSON RODLESS PUMP 2 Sheets-Sheet l Filed NOV. 23, 1945 Juve 12 'a'l" 7? af/JJ: C. Per :7115017 L/ M@ I v Q ZTL/ 51;

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Nov. 9, 1948. l R. c. FERGUSON 2,453,365

RODLESS PUMP Filed Nov. 23, 1945 2 Sheets-Sheet Patented Nov. 9, 1948 UNITED sTATEs PATENT OFFICE RODLESS PUMP Ralph C. Ferguson, Hoilydale, Calif. Application November 23, 1945, Serial No. 630,164 11 claims. (ci. 10s-4s) My invention relates to a. pump designed particularly for oil well use though not necessarily restricted thereto.

In pumping oil from oil wells it is often necessary to raise the oil from depths of many thousand feet. In such cases the use of the ordinary types of pumps involves considerable expense and the use of considerable amounts of power because of the necessity of working long lengths of pump rod, or electrical pumps lowered to the bottom of the well and requiring the use of long lengths of cable, pipe and other equipment.

It is an object of the invention to provide a pump which can be used to raise liquid from any level without the use of pump rods operated from the surface.

It is a further object of the invention to provide a pump operated by pressure intermittently applied to the column of fluid standing in the well to be pumped.

A further obect of the invention is to provide equipment of the kind described of great simplicity and flexibility.

A further obj'ect of the invention is to provide a pump which may be readily adjusted to raise iiuid from the particular depth required by the circumstances.

A further object of the invention is to provide a pump construction requiring a minmum of attention and one which is substantially automatic in operation.

Further objects and features of the invention will appear in theI following description taken in conjunction with the accompanying drawings.

The invention is hereinafter described and illustrated in a preferred form, but it is to be understood that the scope of the invention is not' in any way limited by this illustrative showing but only as indicated by the scope of the claims.

In the drawings: Fig. l is a central section through the upper portion of the pump of my invention, the pump being shown in the uid discharging condition;

Fig. 2 is a section similar to Fig. 1 through the lower portion of the pump;

Fig. 3 is a plan view showing the arrangement of manifolds for delivering air under pressure to the pump;

Fig 4 is a fragmentary section on the line 4--4 of Fig. 1 and to an enlarged scale, showing the flexible diaphragm used for automatically controlling the supply of compressed air to the pump; and

Fig. 5 is an elevational view partly in section of the invention shown with relation to a well.

Referring now to Fig. 1 the numeral I0 indicates the well casing which' is covered by a cap I2 through which a length of tubing or outer tube I4 supported by cap I2 is projected downwardly into the well to the bottom thereof, or

at least to a desired depth below the level of the liquid in the well. Obviously the tubing I4 mw be formed of a plurality of lengths connected together to give the desired length and any changes in they depth at which the pump is to operate may be taken care of by adding or removing lengths of pipe. Tube M is closed at its lower end by a cap i6 furnished with a valve connection I8 through which gas under pressure may be introduced into a balancing chamber I9 located at the bottom of the structure before the pump is placed in the well, at a pressure depending on the 'weight of the column of liquid to be raised. This feature of the invention will be more fully described hereinafter.

An-inner tube or tubing 2U is mounted in the tubing I4 near the lower end thereof and terminates at' its lower end in a sealing gland head 22 serving to guide a piston rod 24 mounted in the inner tube. The upper end of the inner tube is furnished with a ball valve 26 opening upwardly and the upper end of the piston rod is furnished with a piston head 28 sliding within the inner tube and is also furnished with a ball valve 30 opening upwardly. Conduits 3I are arranged adjacent and above the gland 22 to `lead oil from the well casing through the outer and inner tubes into the space between the piston rod and the inner tube.

The purpose of the valve arrangement is to force the iiuid in the pump and well to move in' the required direction and any other arrangement of valves for this purpose may be made. The piston rod is continued below the packing 22 and carries at its lower end a second piston 32 which slides in liquid tight engagement with the wall of the outer tube Id. It is pointed out that liquid within the outer tube Ill is in communication with the liquid above the lower piston head through passages 23 in the sealing gland head 22.

Depending from the lower piston 32, which has a fluid tight t in the lower end of the outer tube, is a cylindrical skirt 34 which is arranged to have an easy sliding t in the lower end of the outer tube I4. The open end of the skirt is sealed by oil introduced through valve I8 in sufilcient amount to seal the open end of the skirt in all positions of the piston.

A pneumatic chamber is thus formed below the' piston 32 which is charged with a suitable gas to a pressure sufficient to balance the static head in the well to be pumped. The upper limit of movement of the lower piston will be when the piston engages against the sealing gland head 22. The engaging surfaces of the sealing gland 22 and piston 32 are arranged so as to insure against escape of gas from the pneumatic chamber when the pressure of a column of oil above the lower piston head is not` acting, as for instance when the pump is initially assembled before being lowered into the well, or when for any other reason the lower piston head is raised to its upper limit of movement by the pressure of the gas under pressure in the skirt; one way of securing the desired result is illustrated in the drawing in which the outer edge oi the lower face of the sealing gland container is provided with an inwardly sloped wall 25 adapted to engage against a cooperating surface 33 formed around the periphery of the upper surface of the lower piston. It will be evident that when surfaces 25 and 33 are engaged the passages for uid through the sealing gland head are blocked ofi.

Mounted on the upper end of the outer tube i@ -is a head 36 serving tc alternately admit a gask such as air under pressure into the upper end of the outer tube and to cut off the supply of pressure air to enable the liquid raised by the expansion oi air sealed in the pneumatic chamber to ilow out of the well. as will now be described.

Various arrangements of heads to eiect functioning of the pump in the required manner may be provided. The means shown in the drawings, by way of example, comprises a head 36 formed to provide a double cylinder 3B, 39, in which a. pair of piston valves du, di, are 'arranged for reciprocation and are connected for simultaneous movement by a rod d2. 'Ihe piston Iii acts to close or open the oil outlet dll and the piston d acts to open and close the inlet from a pipe supplying compressed air.

Compressed air from a suitable source such as an air compressor, not shown, is supplied through main il to a distributor valve 50.

Branch conduits', dii (Fig. 3) deliver air under pressure through inlets '38a and dsa alternately behind the pistons 130, Gi under control ol the distributor valve which vents the space behind the piston to which pressure is not being applied, and admits pressure air to the well through a delivery pipe El. A stem 52 mounted to slide through the head of cylinder 38 moves pivoted lever t, which operates valve rod 56 of a. valve ,E1 in the delivery pipe against the eii'ort oi a spring 55 to admit air flowing through the delivery pipe 5i, when the piston valve iii moves against the stem 52.

When the piston til is reaching the end of its travel opening the air outlet it insures that full pressure is applied to cause displacement oi the pistons before pressure air is directed into the well.

The distributor valve 'il is controlled by means of a flexible diaphragm 5D (Fig. 4) mounted to cover an aperture in the wall of the upper end 0f the outer tube it by means of a housing 6i clamping the perimeter ofthe diaphragm to the tube. The diaphragm is stressed by spring b2 and a rod 8d riveted to the center of the diaphragm operates the distributor valve through any suitable arrangement, as, for example, by means of a ratchet operating a seared wheel td on the shaft l0 of the valve.

The tension of spring 82 may be varied by ad- Justing the threaded sleeve 66, which forms the outer abutment for the spring, in the housing Bi, by means of a handwheel 61 secured to the ,sleeve 86. n

A valve operated by a handwheel 53 enables the rate of iiow oi the compressed air into the well to be varied to control the speed of operation of the pump to suit the rate of iiow of liquid from the earth into the well.

The handwheel 61 (Fig. 4) is' used to adjust the range between the high and low pressure and therefore enables the length of-stroke of the pump to be adjusted.

` Skirt 34 of the proper length is selected for use in the conditions of pressure and/or stroke under which the pump is to operate. If these conditions change or the pump has to be set for use in another well to work under different conditions, the skirt may be readily changed for an' other.

The functioning of the device is as follows. Assuming that the pressure in the upper end of the outer tube has fallen to a point such that the spring 62 opens the branch air supply pipe B9 to admit air behind the piston di, the piston will be driven to the left, as seen in Fig. 3, thus closing oi the oil outlet pipe 4t and opening the air inlet 46 by pushing piston 4i! to the left. The distributor valve is arranged to pass pressure air to the air pipe 5i at the time that air is admitted to branch delivery pipe 39, but air will not be admitted into the controlling head 36 until the piston 40 in its movement to the left operates stem 52 to open valve 57. Air will now flow into the control head at full pressure which may, for instance, be 200 pounds to the square inch, and this pressure will be transmitted through the oil in the outer tube around the inner tube (but is prevented from entering the inner tube by the valve at the upper end of the inner tube) to the upper surface of the lower piston head 32 which will result in compressing the charge of air or other gas trapped in the bottom of the outer tube and in drawing the upper piston head downwardly through the uid standing inside the inner tube, this oil being free to move upwardly through the piston head around the ball valve 3Q.

The pressure will be built upuntil the flexible diaphragm B0 is moved outwardly sufficient to change the setting of the distributor Valve, which will then admit air under pressure through branch air delivery conduit behind piston di), which will thereupon be driven to the right, closing oi the air inlet port d6 and enabling spring 55 to act on lever 5d to close the air delivery valve 5l. The piston 4i will simultaneously be moved to open the oil delivery pipe t6 through which the compressed air at the top of the pump will escape, relieving the pressure on the column of oil in the outer tube. The compressed air in the bottom of the outer-tube wil1 thereupon expand' driving the piston rod 24 upwardly, forcing the oil trapped above the ball valve 30 through the upper ball valve 26 and delivering it from the well throughvthe oil outlet pipe.

Oil in the well casing will iiow through conduits 3l to take the place of the oil which passed upwardly through the piston head 28 on the next downward movement of the rod.

When the pressure in the controlling head yhas again dropped vto a suiliciently low value the valve setting will be changed to again admit air under pressure behind the piston di and the pressure cycle will recommence.

The pump construction lends itself to the operation of a number of pumps from a common pressure main since the flexibility of the construction enables each pump to be set to the conditions to be met in the particular well in which it works.v

' I claim:

1. A piunp including: a length of outer tube closed vat its upper and lower ends and adapted to be positioned within a well; a valve arranged in the closed lower end of said tubing for admitting gas under pressure suiilcient to balance the static pressure of the liquid in the well and forming a pneumatic cushion; a. length of tube positioned within and spaced from said outer tube; means supporting the inner tube within the outer tube, said means being formed `to enable tluid to pass from within said outer tube above said inner tube between the inner `and outer tubes, and to below said inner tube; a nonreturn valve'at the upper end of said inner tube; a sealing gland at the lower end of said inner tube; a piston rod arranged within and spaced from the 'Wall of said inner tube and extending downwardly through said gland; a piston carried at the upper end of said piston rod and sliding in said inner tube; one-way valve means carried by said piston to permit fluid standing between the piston rod and inner tube to flow therethrough on. downward movement of the piston rod; conduits arranged to lead liquid from the well through said outer and inner tubes into the space between said piston rod and the wall of the inner tube; a piston at the lower end of said piston rod sliding ln said outer tube; and means for applying pressure to the upper end of the iiuid column standing in said outer tube to force said piston rod downwardly against the resistance of the pneumatic cushion and to relieve said pressure to enable the compressed air of said pneumatic cushion to discharge fluid carried above the upper piston head from said outer tube and from the well.

2. A pump including: a length of outer tube closed at its upper and lower ends and adapted to be positioned within a well; a valve arranged in the closed lower end of said tubing for admitting gas under pressure sufficient to balance the static pressure of the liquid in the well and forming a pneumatic cushion; a length of tube positioned within and spaced from said outer tube, and means supporting the inner tube within the outer tube, said means being formed to enable iiuid to pass from within said outer tube above said inner tube between the inner and outer tubes, and to below said inner tube; a nonreturn valve at the upper end oisaid inner tube; a sealing gland at the lower end of said inner tube; a piston rod arranged within and spaced from the wall of said inner tube and extending downwardly through said gland; conduits arranged to lead liquid from the well through said outer and inner tubes into the space between said piston rod and the wall of the inner tube; valve means effective to permit downward movement of the piston in said inner tube without displacement of iluid into the well through said conduits; a piston at the lower end of said piston rod sliding in said outer tube; and means for applying pressure to the upper end of the fluid' column standing in said outer tube to force said piston rod downwardly against the resistance of gas trapped inthe bottom of the outer tube below the lower piston head on said piston rod, and to relieve said pressure to enable the compressed gas trapped in the bottom of the outer tube to discharge iluid carried above the upper piston head from said outer tube and from the well.

3. A pump as set forth in claim 2 and in addition comprising a skirt open at its lower end and depending from said piston at the lower end of said piston rod into the outer tube; and a body of oil positioned in the lower end` of said tube serving to seal a body of gas under pressure within said skirt in all positions of the piston.

4, A pump as set forth in claim 2 and in addition comprising a skirt open at its lower end and depending from said piston at the lower end of said piston rod into the outer tube; and a body of oil positioned in the lower end of said tube serving to seal a body of gas under pressure within said skirt in all positions of the piston; passages arranged to permit fluid to ilow from between the inner end and outer tubes into the space below said inner tube; and parts on the lower piston arranged to seal said passages when at its upper limit of movement to prevent the gas forming the pneumatic cushion from leaking into the pump when the pump is not under load.

5. A pump including: a length of outer tube closed at its -upper and lower ends and adapted to be positioned within a well; a valve arranged in the closed lower end of said tubing for admitting gas under pressure suliicient to balance the static pressure of the liquid in the well and forming a pneumatic cushion; a length of tube positioned within and spaced from said outer tube; means supporting the inner tube within the outer tube, said means being formed to enable uid to pass from within said outer tube above said inner tube between the inner and outer tubes, and to below said inner tube; a nonreturn valve at the upper end of said inner tube; a sealing gland at the lower end of said inner tube; a piston rod arranged within and spaced from the wall of said inner tube and extending downwardly through said gland; conduits arranged to lead liquid from the well through said outer and inner tubes into the space between seid piston rod and the wall of the inner tube; valve means effective to permit downward movement of the piston in said inner tube without displacement of fluid into the well through said conduits; a piston at the lower end of said piston rod sliding in said outer tube; means for applying pressure to the upper end of the fluid column standing in said outer tube to force said piston rod downwardly against the resistance of said pneumatic cushion and to relieve said pressure to enable the compressed air trapped in the bottom of the outer tube to discharge fluid carried above the upper piston head from said outer tube and from the well; and pressure responsive means actuated by the pressure in the top of the outer tube to automatically apply and release pressure on'the top of the column of oil in the pump to operate it.

6. A pump for forcing uid from a well including: a5 tubular structure adapted to be suspended in the well; a piston rod reciprocably mounted in said tubular structure; an upper piston mounted at the upper end of said piston rod and a lower piston mounted at the lower end of said piston rod; said upper piston being provided with a passage therethrough controlled vby an upwardly opening check valve means for intermittently imposing pressure from 'the top of the well through the liquid to be pumpedA to the upper face of the lower piston while preventing said pressure from being imposed on said upper piston; a pneumatic Acushion provided by a charge of gas trapped in said tubular structure below said lower piston and acting to balance the static pressure in the well; and inlet means admitting iluid from the well into the tubular structure between said piston to be raised by the upper piston when said pressure is relieved; said tubular structure providing an outlet to the suriace of the ground for well fluid pumped by said upper piston.

7. In a pump for forcing fluid from `a well, a tubular structure adapted to be suspended in the well; a piston supporting element mounted for reciprocable movement in said tubular structure; an upper piston mounted at the upper end of said element and a lower piston mounted at the lower end ofsaid element; said tubular structure providing an outlet conduit means for uid pumped by said upper piston; means for intermittently imposing pressure from the top of the well through the liquid to be pumped to the upper face of the lower piston while preventing said pressure from being imposed on said upper piston; a pneumatic cushion provided by a charge of gas trapped in said tubular structure below said lower piston and acting to balance the static pressure in the well; and inlet means admitting uid from the well into the tubular structure to be raised by the upper piston when said pressure is relieved, said upper piston being provided with an upwardly opening check valve permitting upward flow of iluidtherethrough upon down-` ward movement of the piston.

8. In a, pump for forcing iluid from a well and adapted to be operated by the application of pressure intermittently to the fluid in the well at the top of the well, a tubular structure adapted to be suspended in the well; a piston rod mounted for reciprocable movement in said tubular structure; said tubular structure providing an outlet conduit means for fluid pumped by said upper piston, an upper piston mounted at the upper end vof said rod and a lower piston mounted at the lower end of said rod; means establishing communication between the fluid in the well above the pump and the upper surface of the lower piston; a pneumatic cushion provided by a charge of gas trapped in said tubular structure below said lower piston and acting to balance the static pressure in the well; and inlet means admitting iluid from the well into the tubular structure to be raised by the upper piston when the pressure imposed at the top of the well is released, said upper piston being provided with an upwardly opening check valve permitting upward flow of uid therethrough upon downward movement of the piston.

9. In-va pump for forcing iluid from a well and adapted to be operated by the application of pressure intermittently to the fluid in the well at the top of the well, a length of outer tubing closed at its( upper and lower ends and adapted to be positioned in a well; a length of inner tubing within and spaced from said outer tubing; means supporting the inner tubing within the outer tubing, said means being formed to enable iluid to pass between the inner and outer tubings longitudinally thereof; a non-return valve at the upper end of said inner tube; a sealing gland at the lower end of said inner tubing; a piston rod arranged within and spaced from the wall of said inner tubing and extending downwardly through said gland; a piston carried at the upper end of said piston rod and sliding in said inner tubing; one-way valve means carried by said said outer and inner tubings into the space be? tween said piston rod and the wall of the `inner tubing; a piston at the lower end of said piston.

rod sliding in said outer tubing; and a quantity of gas under pressure suflicient to balance the static pressure of the liquid in the well forming a pneumatic cushion beneath said lower piston.

10. In a pump for forcing iluid from a well and adapted to be operated by the application of pressure intermittently to the iluid in the well at the top of the well, a length of outer tubing closed at its upper and lower ends and adapted to be positioned in a well; a length of inner tubing Within and spaced from said outer tubing; means supporting the inner tubing within the outer tubing, said means being formed to enable iiuid to pass between the inner and outer tubings longitudinally thereof; a non-return valve at the upper end of said inner tube; a sealing gland at the lower end of said inner tubing; a piston rod arranged within and spaced from the wall of said inner tubing and extending downwardly through said gland; a piston carried at the upper end of said piston rod and sliding in said inner tubing; one-way valve means carried by said piston to permit fluid standing between the piston' rod and inner tube to flow therethrough on downward movement of the piston rod; said inner tubing above said piston and said outer tubing above said inner tubing constituting an outlet for uid pumped by said piston; an inlet conduit arranged to lead liquid from the well through said outer and inner tubings into the space between said piston rod and the wall of the inner tubing; a piston at the lower end of said piston rod sliding in said outerI tubing; and a quantity of gas n under pressure sufficient to balance the static pressure of the liquid in the well forming a pneumatic cushion beneath said lower piston; a skirt open at its lower end and depending from said piston at the lower end of said piston rod; and a body of oil positioned in the lower end of said tube serving to seal a body of gas under pressure within said skirt in all positions of the piston.

11. In a pump for forcing fluid from a well and adapted to be operated by the application of pressure intermittently to the fluid in the well at the top thereof, a length of tubing in said well extending from the top of the well to below the normal iluid level in the well; a tubular structure supported by said tubing in the lower end portion thereof; a piston rod mounted for reciprocal movement in said tubular structure; a pump piston and a gas cushioned piston mounted on said rod in vertically spaced relation; said tubular structure and said gas cushioned piston cooperating to form an enclosed gas chamber; a pneumatic cushion provided by a charge of gas in said chamber; said tubing and tubular structure providing communication. between the interior of said tubing above said tubular structure and the surface yof said gas cushioned piston outwardly of the gas chamber for the application of pressure to the gas cushioned piston and providing communication between said pump piston and the interior of said tubing above said tubular structure for the outlet ofl fluid pumped by said pump piston; means providing a well iluid inlet passage from a point externally of said tubing to UNITED STATES PATENTS the region of said pump piston;4 an upwardly opening check valve in said tubular structure and Number Name Date positioned in the general region of said pump 2,384,173 Johnston Sept. 4, 1945 piston; and an upwardly opening check valve in 5 Said pump Piston FOREIGN PATENTS RALPH C. FERGUSON.

REFERENCES CITED The following references are of record in the lo file of this patent:

Number Country Date 2,949 Great Britain 186i 

